If I understand you correctly, his income would have been tripled for federal income tax purposes also. There is room on one W-2 form to enter wage and withholding information for two states, and I don't think TN needs to be mentioned at all since there is no personal income tax there. It sounds like whoever prepared the W-2 forms made a major error here. I believe you should check with your husband's company regarding having them correct the W-2 forms with the IRS and each state.
You may also want to check with the IRS about this because you will more than likely need to file an extension until the corrections are made unless the IRS has a better suggestion. I would file an extension anyway (both federal and state) and then keep trying to contact the IRS and state governments on this also. Maybe they can give you some good "official" advice on this.
